The present invention relates to a steering drive axle, particularly for agricultural tractors and earth-moving machines, of the type comprising:
a central oscillating body containing a differential unit, articulated suspension means for supporting respective wheel hubs for pivoting in a transverse vertical plane, and transverse transmission members for transmitting the rotary drive from the differential unit to the wheel hubs, the transverse transmission members being articulated in order to follow the vertical pivoting and the steering movement of the hubs.
An axle of this type is described in the Applicant's Italian patent application No. PD96A000120.
The transverse transmission members usually comprise an articulated half-shaft, typically split up into four successive portions connected by joints. More precisely, a first, innermost portion takes the drive from the differential situated in the central portion of the axle and transfers it, by means of a first universal joint, to a second half-shaft portion which is connected, by means of a second universal joint, to a third half-shaft portion which introduces the drive to a double universal constant-velocity joint; the third portion is supported for rotation by the hub support. The fourth, outermost portion extends from the outer side of the constant-velocity joint and rotates the hub.